 I know cycling is always a more favorable choice than a bus . After all , it's a sport . But do you think it a pleasant experience to take in the dirty , polled air on the road ? 
 Well , such things are just unavoidable in a great metropolis like Beijing . I think a still more desirable benefit is psychological . Bicycling home after work can help release your stress . Life in the offices is miserable . You just sit there in a daze , gazing at the monitor and dealing with files and documents . Why don't you give a full play to your energy after work ? Enjoy the speed on the road . Just think , you are flashing past the poles with your own energy . How great ! 